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* various smaller changesChristopher Vogt2017-02-091-0/+8
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* replace flawed concurrent hashmap cache with consistent replacementChristopher Vogt2017-02-011-3/+1
| | | | | | | | | | | | | | | | | | | | | | | The concurrent hashmap approach to classloader caching was flawed. Assume you have two concurrently running builds A and B and projects P2 and P3 depending on project P1. And assume a time sequence where A compiles P1, then compiles P2, then P1’s sources change, then B compiles P1, then A compiles P3. At the end P2 and P3 will have different versions of P1 as their parent classloaders. This is inconsistent. The easiest way to work around this is making sure only one thread is changing the classloader cache during it’s entire run. This would mean either no concurrency or what we have done here, which is letting threads work on a copy of the cache and replace the original cache in the end using an atomic operation. This means the thread that finishes last wins, but for caching that’s fine. Worst case some things aren’t cached in a concurrent execution. This change also means that we don’t need concurrent hashmaps for the classloader cache anymore since no two theads will access the same hashmap. We still need a concurrent hashmap for the class caches inside of the classloaders as multiple threads can access the same classloaders.
* Merge separate hashmaps for persistent cache into oneChristopher Vogt2017-02-011-26/+25
| | | | | | | This isn’t type-safe, but re-using that same hashmap for both keys and classloaders allows to reduce the number of members in Context. Also we can re-use the same hashMap for other things as well in the coming commits, e.g. timestamps.
* Reproducible builds, composing different CBT version and various improvementsChristopher Vogt2016-04-281-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One large commit, because it is was hard to do these things in isolation or to separate them now. CBT now knows how to load other versions of itself - Support for reproducible builds (!), by providing a CBT git URL and hash to tie build to - Support for composing builds using different CBT versions (!) - introduce (in compatibility/) Java interfaces all CBT versions need to stay compatible with, so they can talk to each other. And put extension methods to these interfaces in cbt package object Class loading - add some sanity checks for class loading - improve class loader invalidation to fix bugs - implement caching in Java land class loaders. In particular to prevent the system class loader to repeatedly generate ClassNotFound exceptions in each sink of the class loader DAG for non JDK classes (meaning major speed up for projects with many classes). - getting rid of transient class loader cache unifying into "persistent" one instead (which is still wrong as invalidation eventually needs to invalidate entire sub graphs of the class loading DAG, not single class loaders. Seems like we'll have to abandon the hashmap based approach and tie caching to dependency objects) Other Caching - cache dependencies extracted from xml files, which was one major time killer, but invalidate cache when cbt changed (maven dependency user facing api needs simplification now!) - memorize last successful compile time in the file system rather than memory, to guard against unnecessary recompiling even across launches (or when using cbt direct) Structural improvements - Factor out ClassLoaderCache on Java land into its own class. - Port MultiClassLoader to Java land, to better compose classloaders in NailgunLauncher. - Remove many global constants and variables (in object paths and in NailgunLauncher) and pass them through instead. Needed for composing of builds. - move more code from resolver into Lib for less entanglement with classes (needed to compatibility interfaces) and better re-usability - remove canBeCached. Everything can be cached now, but we need to be careful about correct invalidation. - remove build announcing produced jars. We can add if ever needed. - change callNullary to return exit code instead of Unit as preparation for next commit introducing "recursive" ScalaTest - Makes ScalaTest support work (still a bit too inflexible, but mostly works well)
* KeyLockedLazyCache was locking on the wrong object. Also added update methodChristopher Vogt2016-03-301-1/+8
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* move KeyLockedLazyCache to its own fileChristopher Vogt2016-03-191-0/+47
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* Refactored ClassLoaderCache to use key locked cache to pave the way for ↵Christopher Vogt2016-03-191-33/+0
| | | | caching classloaders hierarchically without deadlocks
* A draft implementation that runs builds concurrently (probably buggy right ↵Christopher Vogt2016-03-121-0/+33
now). Is CBT "reactive" now ;)?